Large areas are generally favored for bird conservation, whereas small areas resulting from habitat fragmentation tend to be ignored, despite their potential to host great diversity. To determine its potential value as a bird conservation area, we surveyed the avifauna of a 30-hectare dam and adjacent land at Mompaní, nearby Queretaro City, Mexico. We recorded 113 bird species which represent 61.7% of the avian records for similar habitats at a regional scale. Mompaní has four species listed in Mexican conservation laws, two of which are threatened: Anas platyrhynchos diazi (Mexican Duck) and Accipiter gentilis (Northern Goshawk), and two subject to special protection: Accipiter striatus (Sharp-shinned Hawk) and Tachybaptus dominicus (Least Grebe). The latter probably uses the area for breeding. We believe that spatial heterogeneity, vegetation structure, and flora composition explained the wealth of birdlife. Mompaní is a favorable place to feed and shelter many birds in the region. Such species richness in a small area should not be ignored, and we recommend that greater attention should be given to conservation actions at this locality, as well as in other small areas with similar ecological conditions, especially in high risk environments such peri-urban areas.